1. Field of the Invention
The present invention relates to the field of printed circuit boards, connectors and chip packaging technologies.
2. Description of the Background
In FIG. 1a, a printed circuit board (PCB) such as a motherboard 10 carries many different components (12-54). A component placed on motherboard 10 may be an integrated circuit chip or a discrete component. Because motherboard 10 supplies signals having certain characteristics and specifications, the components that can be inserted onto motherboard 10 must meet the specifications. A component that does not meet the specifications cannot be inserted directly onto motherboard 10. For instance, motherboard 10 used in a computer typically provides power supply voltages between 4.75 V to 5.25 V. Suppose that component 24 includes a processor that runs at high speed such as a 66 MHz (PENTIUM) processor. For component 24 to be inserted directly onto motherboard 10, it must be able to operate using power supply voltages between 4.75 V and 5.25 V. However, if the processor requires different power supply voltages (e.g., 4.9 V to 5.4 V, 5.15 V to 5.4 V or 3.0 to 3.3 V) due to manufacturing process variations or design changes, it cannot be inserted onto motherboard 10.
There are two possible solutions. First, motherboard 10 can be redesigned with a separate power distribution trace for the processor. There are several disadvantages to this approach. One is the cost. Redesigning an entire motherboard that is to be used with many components is very costly. Also, it may be too time consuming. It may take a considerable amount of time to redesign the motherboard. In addition, a motherboard used for a computer typically requires an FCC certification. If the motherboard is redesigned, it may also need an FCC re-certification.
Second, instead of redesigning the entire board, an interface adapter board may be employed. One advantage of having an interface adapter board is that it would not require an FCC re-certification. A prior art interface adapter board 55 may have a switching power supply converter 56, component 24, an array of connectors 57 and long metal traces 58. Switching power supply converter 56 converts power supply voltages from one range to another range that is compatible with component 24. When component 24 has an array of pin connectors (such as pins 72 in FIG. 4a), component 24 needs to be displaced laterally at least by the size of the array of the pin connectors. When a conventional connector technology is used, component 24 is connected to motherboard 10 through long metal traces 58 (not all are shown) and array of connectors 57. This solution, however, is not acceptable when the operating speed of component 24 is high (e.g., 66 MHz). For a high speed component, the interface adapter board must be designed to minimize the amount of adverse effect it has on the timing of the signals and the transmission line characteristics of component 24 and motherboard 10.